Hemorrhage from Subependymoma of the Septum Pellucidum
Subependymoma of the septum pellucidum presenting as subarachnoid hemorrhage 1).
Subependymomas (SEs) are rare, benign, noninvasive, slow-growing tumors located anywhere along the ventricular walls. They arise most frequently in the fourth ventricle followed by the lateral ventricle, and less frequently in the septum pellucidum, third ventricle, and spinal cord. Most SEs are found incidentally at autopsy, but some may produce clinical symptoms. Tumor-related hemorrhage represents an extremely rare presentation sign. Kawahara et al. described a rare case of septum pellucidum SE as a tumoral hemorrhage. The tumor was totally removed via an interhemispheric transcallosal approach. The histological examination found typical SE. Although the patient had transient memory impairment, he had a good postoperative course and was discharged on the twenty-first postoperative day. 2)
A 32-year-old man presented with subependymoma in the lateral ventricle causing intraventricular hemorrhage and manifesting as severe headache and disturbance of consciousness. Computed tomography on admission showed a massive intraventricular hemorrhage and acute obstructive hydrocephalus. Cerebral angiography revealed no abnormal findings. Emergency external ventricular drainage was performed, and his neurological deficits gradually improved. Magnetic resonance imaging at 5 weeks after admission showed a tumor arising from the septum pellucidum or the floor of the right lateral ventricle, appearing as a mixed-intensity solid tumor, which was partially enhanced following gadolinium administration. The tumor had arisen from the septum pellucidum and was totally removed via an interhemispheric anterior transcallosal approach. Histological examination found typical subependymoma, with little vascularity. Intraventricular hemorrhage from cerebral neoplasms is usually due to highly vascular tumors. Since subependymomas are quite benign and show poor vascularity, intraventricular or subarachnoid hemorrhages are very rare, but do occasionally occur 3).
A 63-year-old man was admitted to our hospital because of loss of memory, disorientation, nausea, and urinary incontinence. Cerebral computed tomographic and magnetic resonance imaging scans revealed a tumor with intratumoral hemorrhage affecting the corpus callosum and the septum pellucidum. A partial resection of the tumor was performed, but the patient died the next day from an episode of bleeding. Postmortem examination revealed a highly vascularized subependymoma with acute bleeding in the tumor and in the surrounding brain parenchyma. The importance of considering a highly vascularized subependymoma is noted when a tumor related to the ventricular system is diagnosed 4).